Perception Enhanced Virtual Environment for Maritime Applications

This paper presents the development of a realtimeperception enhanced virtual environment for maritimeapplications which simulates real-time six degrees of freedomship motions (pitch, heave, roll, surge, sway, and yaw) underuser interactions, environmental conditions and various threatscenarios. This simulation system consists of reliable shipmotion prediction system and perception enhanced immersivevirtual environment with greater ecological validity. Thisvirtual environment supports multiple-display viewing that cangreatly enhance user perception and we developed the ecologicalenvironment for strong sensation of immersion. In this virtualenvironment it is possible to incorporate real world ships,geographical sceneries, several environmental conditions andwide range of visibility and illumination effects. This system canbe used for both entertainment and educational applications suchas consol level computer games, teaching & learning applicationsand various virtual reality applications. Especially this framework can be used to create immersive multi user environments

Poster Abstract: Temperature Hints for Sensornet Routing

ABSTRACT Real-world experiments have shown that the transmission power and the received signal strength of low-power radio transceivers used in sensornets decrease when temperature increases. We analyze how this phenomenon affects the network layer, and find that temperature fluctuations may cause undesirable behavior by sensornet routing protocols such as CTP and RPL. Furthermore, we present an approach to make these protocols robust to temperature fluctuations by augmenting the ETX link metric with temperature hints

A framework for multiparty communication types

There are large number of communication paradigms such as multicast and anycast that are useful for distributed applications. The spectrum of such communication paradigms is larger than immediately apparent from the names used to identify these communication paradigms. None of these communication paradigms are universally available in the global Internet. To use these paradigms in applications programmers have to compose them using point-to-point communication or use third party modules that do so. Application level overlay networks have been used to implement some of these communication paradigms. These works indicate the vast design space behind the implementation of each of these multiparty communication paradigms over the wide area Internet. Application programmers should be able to make use of communication paradigms independent of their implementations and the implementors of communication paradigms should be able to explore the design space of implementing them. The lack of three components inhibits achieving these goals; a naming system that can accommodate current and future communication paradigms, a common application programmer's interface (API), and a system to deploy the implementations of communication paradigms. This dissertation describes a framework named MayaJala, based on the novel notion of multiparty communication types, that addresses these issues; multiparty communication types are the precisely defined counterparts of multiparty communication paradigms. MayaJala consists of two main components; a communication type system and a middleware system. The multiparty communication type system provides a mechanism to precisely identify communication paradigms. It also provides the ability to explore useful properties such as the equivalence of two communication types and conformance of one communication type to another. This allows applications to use different implementations of conforming communication types and not just different implementations of a single communication type. The multiparty communication type system also yields a common and simple interface sufficient for all the communication types. The middleware allows dynamic deployment of implementations transparent to the applications and also provides common functionality required by these implementations. The middleware provides support to implement communication types using application-level overlay networks. The middleware, together with the idea of multiparty communication types, facilitates the deployment of implementations of communication types without any coordination of the processes that participate in a session. This work shows that it is possible to provide a naming system, and a simple and common API for multiparty communication paradigms without restricting or standardizing the set of such communication paradigms. This is achieved through the notion of multiparty communication types. This work also shows that multiparty communication types can be deployed without any coordination from the processes participating in a session. MayaJala provides these facilities with a minimum overhead to the applications that use it.Science, Faculty ofComputer Science, Department ofGraduat

A network processor based message manager for MPI

We have implemented a system called MPI-NP II, which is an MPI specific messaging system for the Myrinet System Area Networks (SAN). It consists of a lowlevel message manager executing on the LANai processor of the Myrinet Network Interface Card (NIC), a thin host interface layer, and LAM-MPI, a public domain version of MPI. MPI-NP II is a re-design of MPI-NP that simplifies and improves the performance of the original implementation. MPI-NP differs from other low-level messaging systems in that it off-loads some of the MPI specific communication tasks onto the network processor. In particular, it manages MPI message envelopes and can progress messages asynchronously from the host. It realizes three of the goals stated in the MPI standard, namely; zero-copy messaging, overlap of communication and computation, and off-loading tasks to a communication co-processor. In addition, it greatly simplifies and reduces host/NIC interaction and makes it possible to support broadcasting on the NIC. The design MPI-NP II introduces the concept of a microchannel, which is analogous to an independent thread on the NIC whose task is to deliver a specific message. The message manager allows for multiple outstanding send/receive requests and guarantees message delivery based on the available envelope resources, independent of the message size. We achieve these design goals without unduly burdening the slow network processor. MPI-NP II has a minimum message latency of 22 microseconds and a maximum bandwidth of 92MB/s. These values are comparable to other low-level messaging systems but with the added benefit of being able to overlap communication and computation.Science, Faculty ofComputer Science, Department ofGraduat

Poster Abstract: Temperature Hints for Sensornet Routing

Real-world experiments have shown that the transmission power and the received signal strength of low-power radio transceivers used in sensornets decrease when temperature increases. We analyze how this phenomenon affects the network layer, and find that temperature fluctuations may cause undesirable behavior by sensornet routing protocols such as CTP and RPL. Furthermore, we present an approach to make these protocols robust to temperature fluctuations by augmenting the ETX link metric with temperature hints.RelyOnI

Hot packets:a systematic evaluation of the effect of temperature on low power wireless transceivers

Temperature is known to have a significant effect on the performance of radio transceivers: the higher the temperature, the lower the quality of links. Analysing this effect is particularly important in sensor networks because several applications are exposed to harsh environmental conditions. Daily or hourly changes in temperature can dramatically reduce the throughput, increase the delay, or even lead to network partitions. A few studies have quantified the impact of temperature on low-power wireless links, but only for a limited temperature range and on a single radio transceiver. Building on top of these preliminary observations, we design a low-cost experimental infrastructure to vary the onboard temperature of sensor nodes in a repeatable fashion, and we study systematically the impact of temperature on various sensornet platforms. We show that temperature affects transmitting and receiving nodes differently, and that all platforms follow a similar trend that can be captured in a simple first-order model. This work represents an initial stepping stone aimed at predicting the performance of a network considering the particular temperature profile of a given environment

A Public Transport System Based Sensor Network for Road Surface Condition Monitoring

A well maintained road network is a must for the economic development and the well being of people in any country. Unfortunately, most developing countries do not poses such road networks. While the lack of funds is mainly to blame for not building new road networks and maintaining the existing ones the lack of proper monitoring and reporting system is a major contributory factor for the dilapidated condition of road networks in third world countries. A case in point is the road network in Sri Lanka; Sri Lanka has an extensive road network that spans the country and new roads are being built every day, yet even the roads in the capital city are not maintained properly. The lack of a monitoring and reporting mechanism is apparent in this case. We propose a public transport system based sensor network to monitor road surface condition. We are currently building such a network called BusNet to monitor environmental pollution and that system can be extended for road surface condition monitoring by adding acceleration sensor boards to the system